046 IgA vasculitis/Henoch-Schonlein purpura complicated by digital gangrene associated with large vessel vasculitis and positive lupus anticoagulant

Abstract

Background: IgA vasculitis (IgAV), previously known as Henoch-Schonlein purpura (HSP), is a relatively common vasculitis of childhood typically presenting with abdominal pain, purpura, large joint oligoarthropathies and renal involvement. Renal involvement is usually self-limiting, however long term complications are more common in older children and adults and range from nephrotic and nephritic syndromes to fulminant renal failure. Classed as an immune-complex mediated small vessel vasculitis, there have been a number of documented cases of concurrent small and medium vasculitis, but only one other report of large vessel vasculitis with IgA nephropathy. Methods: We describe a patient with a background of IgAV and IgA nephropathy who developed large vessel vasculitis and positive lupus anticoagulant with critical limb ischaemia 10 months after a relapse of cutaneous IgAV. Results: A 29 year old male developed typical HSP aged 14 with IgA nephropathy resulting in end stage renal failure requiring dialysis. He presented with several months of intermittent purpura over his lower limbs and buttocks not associated with any other symptoms of HSP. He was commenced on 10mg oral prednisolone, which suppressed the purpura. However, he progressed to develop ischaemic gangrene and necrotic ulcers over the dorsal surface of his toes and the right heel. Punch biopsy demonstrated IgA deposition with an early leukocytoclastic vasculitis. He reported right sided calf claudication and rest pain at night. Pedal pulses were absent bilaterally and capillary refill was grossly delayed. C-reactive protein was mildly raised (10mg/L). He tested positive twice for the lupus anticoagulant with negative anticardiolipin and b2GP1 antibodies. Arterial Doppler ultrasound showed extensive bilateral disease, most marked on the right. He underwent a superficial femoral artery and popliteal angioplasty. A PET CT confirmed an underlying large vessel vasculitis with increased uptake in the subclavian, brachiocephalic, abdominal aortic, iliac and femoral arteries. He was started on mycophenolate mofetil as well as treatment dose dalteparin followed by warfarin. Clinically he responded well, with clearance of his purpura and almost complete healing of the ischaemic lesions. Conclusion: To our knowledge, this is only the second description of large vessel vasculitis complicating IgAV and the first to be associated with a positive lupus anticoagulant. Although IgAV is usually a selflimiting condition, adults are more likely to relapse and may require immunosuppression. Testing for antiphosholipid antibodies is worth considering especially in the presence of digital ischaemia.